P1(3) Flashcards
What happens if you use a cathode?
Positive ions gain electrons - reduction
What happens if you use a anode?
Negative ions give up (lose) electrons - oxidation
Where does electrolysis occur?
In a cell , substance to be decomposed is called the electrolyte and the current is passed into and out of the electrolyte by electrodes
What happens if sodium chloride dissolved in water ?
It’s ions become free to love so the solution can be electrolysed
What is a catalyst?
A chemical which is added to a reaction to speed up but can recovered at the end unchanged
What does a catalyst provide ?
An alternate reaction pathway with a lower activational energy
Where does the word redox come from?
Reduction and oxidation , takes place together
What is the test for oxygen?
Glowing splint
What is the test for carbon dioxide ?
Limewater goes cloudy
What is the test for hydrogen?
Squeaky pop
What are chemical changes ?
Chemical reactions often involve changes in energy due to the breaking and formation of bonds
What are chemical changes ?
Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances.
Define a mole
A mole of a substance is defined as: The mass of substance containing the same number of fundamental units as there are atoms in exactly 12.000 g of 12C.
How many carbons are in methane , ethane , propane , butane and pentane ?
Methane=1 Ethane=2 Propane =3 Butane=4 Pentane =5
What is the difference between alkenes and alkanes ?
Alkanes only contain single bonds , alkenes contain a double bond
